(a) Field of the Invention
The present invention relates to a manufacturing method of a liquid crystal display (“LCD”), and an LCD manufactured thereby. More particularly, the present invention relates to a manufacturing method of an LCD including a feature to repair a pixel defect in a minute branch pixel electrode structure which would otherwise result in an unwanted turned-on pixel when the LCD received instructions to display a black screen, and an LCD manufactured by the method.
(b) Description of the Related Art
Among display panels, an LCD is one type of flat panel display which is currently being widely used, and includes two display panels in which field generating electrodes such as a pixel electrode and a common electrode, etc., are formed, and a liquid crystal layer is disposed therebetween. The two display panels of the liquid crystal display typically include a thin film transistor (“TFT”) array panel and a common electrode panel, respectively, and a pixel electrode of the TFT array panel and a common electrode of the common electrode panel are applied with voltages to generate an electric field in the liquid crystal layer disposed therebetween, and thus orientation directions of liquid crystal molecules of the liquid crystal layer are determined by the applied voltages and polarization of incident light is controlled by the liquid crystal molecules so as to display an image.
The TFT array panel typically includes signal lines such as a gate wire and a data wire, a transparent pixel electrode, a color filter, and a black matrix, and the common electrode panel typically includes a common electrode. Alternatively, the color filter and the black matrix may be formed in the common electrode panel.
Among the various types of LCDs, a normally black mode vertical alignment (“VA”) mode display displays a black image when a voltage difference between two display panels is zero.
Various display defects of the LCD can occur, and a pixel defect in which a pixel is turned on, e.g., allows light from a backlight to pass therethrough to be perceived by a viewer, when the LCD is instructed to display a black image is a representative defect. This defect will hereinafter be referred to as a pixel shining during a black screen image for brevity of explanation.
To repair the pixel defect in which the pixel shines during the black screen image, even if the defect occurs among several unit pixels of the LCD, a drain electrode connection of a TFT of the defective pixel is typically cut by a laser so that the drain electrode and pixel electrode of the defective pixel are not applied with a data voltage, and thereby the pixel electrode is electrically floated and the voltage difference between the pixel electrode and the common electrode disappears, and as a result the black state is always maintained.
However, in the case of a conventional minute branch pixel electrode structure, a portion of the drain electrode connection and the edge connection is covered by a light blocking layer to prevent a light leakage phenomenon such that it is impossible to irradiate a laser onto the drain electrode, i.e., the laser would be blocked by the light blocking layer, and thereby it is difficult to repair the pixel defect.
Also, due to this problem, although the portion of the drain electrode that is not covered by the light blocking layer may be irradiated by the laser for cutting, the data voltage may still be applied to the pixel electrode through the edge connection, and thereby the pixel defect is not repaired.